|Cell Wall Absent
- Person-to-person transmission is via inhalation of contaminated respiratory droplets. children, adolescents, and young adults (Ages 5-20) appear to be the most prone to infection although any age group can be affected.
- Clinical consequences following infection usually require a prolonged incubation time of 2-3 weeks. When they do arise, they are characterized by mild constitutional symptoms typified by low fever and headache. Cough is a prominent symptom and is usually dry and non-productive. A small minority of patients develop an atypical community-acquired pneumonia. Infection is self-limited in most cases.
- A notable feature of M. pneumoniae infection is the development of "Cold Agglutinins". These are antibodies which can agglutinate erythrocytes only at low temperatures. Consequently, blood from an infected individual will aggregate when placed on ice. It is thought that a surface antigen on M. pneumoniae mimics a normal surface antigen of RBC's and that the immune response to M. pneumoniae results in synthesis of a cross-reacting antibody.
- Erythromycin or doxycycline may shorten length of symptoms.